A heat transfer circuit includes a compressor, a condenser, an expander, and an evaporator that are fluidly connected together. The compressor includes a housing and a shaft rotatable relative to the housing to compress a working fluid received at a suction inlet, in which the shaft is supported by a gas bearing, and the gas bearing including a bearing housing having a fluid inlet and an outlet. A high pressure gas source is fluidly connected to the fluid inlet of the bearing housing for supplying high pressure fluid to the fluid inlet of the gas bearing such that the gas bearing supports the shaft when the shaft is rotating. A pressure reducer is connected to the outlet of the gas bearing is provided for reducing a vent pressure of the gas bearing.

Provided is a waterproof fan which includes: a rotor; a stator including a winding; a circuit board supplying power to the winding; a resin frame including an undersurface located on one side of a rotation axis of a rotor, and a housing space opening on the other side of the rotation axis, to house the circuit board; a waterproofing resin portion covering the stator and closing an opening of the housing space; a bearing rotatably supporting the rotating shaft portion; and a cylindrical metal bearing holder extending along the rotation axis and supporting the bearing, in which the frame includes a tubular holder protection portion extending from the undersurface to the other side of the rotation axis and covering at least a part of an outer peripheral surface of the bearing holder, and the holder protection portion separates the stator from the bearing holder.

A blower includes a fan and a motor, wherein the motor includes a shaft, a bearing that supports the shaft, and a motor case that covers at least a part of the bearing, the fan includes a main plate having a first surface facing the motor case and a second surface opposite to the first surface, and connected to the shaft, and a plurality of blades erected on the second surface of the main plate, and arranged radially with respect to an axis of the shaft, at least one of the fan and the motor case includes blocking members, and each of the blocking members is located apart from the shaft between the first surface of the main plate and the motor case, and surrounds the shaft.

A blower includes a fan and a motor, wherein the motor includes a shaft, a bearing that supports the shaft, and a motor case that covers at least a part of the bearing, the fan includes a main plate having a first surface facing the motor case and a second surface opposite to the first surface, and connected to the shaft, and a plurality of blades erected on the second surface of the main plate, and arranged radially with respect to an axis of the shaft, at least one of the fan and the motor case includes blocking members, and each of the blocking members is located apart from the shaft between the first surface of the main plate and the motor case, and surrounds the shaft.

A centrifugal compressor, including: a housing; a motor assembly disposed in the housing and a motor cavity and a motor shaft located in the motor cavity, the motor shaft having a first end and a second end extending from the motor cavity; a first impeller assembly located at the first end of the motor shaft and provided with a first labyrinth sealing mechanism; a second impeller assembly located at the second end of the motor shaft and provided with a second labyrinth sealing mechanism; a first gas bearing assembly provided between the motor cavity and the first impeller assembly; and a second gas bearing assembly provided between the motor cavity and the second impeller assembly; wherein the first labyrinth sealing mechanism is kept in gas communication with the first gas bearing assembly, and the second labyrinth sealing mechanism is kept in gas communication with the second gas bearing assembly.

A centrifugal compressor, including: a housing; a motor assembly disposed in the housing and a motor cavity and a motor shaft located in the motor cavity, the motor shaft having a first end and a second end extending from the motor cavity; a first impeller assembly located at the first end of the motor shaft and provided with a first labyrinth sealing mechanism; a second impeller assembly located at the second end of the motor shaft and provided with a second labyrinth sealing mechanism; a first gas bearing assembly provided between the motor cavity and the first impeller assembly; and a second gas bearing assembly provided between the motor cavity and the second impeller assembly; wherein the first labyrinth sealing mechanism is kept in gas communication with the first gas bearing assembly, and the second labyrinth sealing mechanism is kept in gas communication with the second gas bearing assembly.

The bearing arrangement includes a one-piece gas bearing sleeve (32) configured to rotatably support the drive shaft (4) and made in molybdenum or in a molybdenum alloy, the one-piece gas bearing sleeve (32) including a radial bearing surface (33) configured to Surround the drive shaft (4).

The bearing arrangement includes a one-piece gas bearing sleeve (32) configured to rotatably support the drive shaft (4) and made in molybdenum or in a molybdenum alloy, the one-piece gas bearing sleeve (32) including a radial bearing surface (33) configured to Surround the drive shaft (4).

The present invention provides a fan motor which includes a housing, a stator disposed inside the housing, a rotor disposed inside the stator, a blade coupled to the rotor and a printed circuit board disposed under the blade, wherein the housing includes an upper housing and a lower housing, wherein a board coupling portion to which the printed circuit board is coupled is disposed concavely formed at a lower outer surface of the lower housing, and the first mounting portion of the printed circuit board is coupled to the board coupling portion, wherein the board coupling portion includes a component hole and the component hole is disposed between an outer circumferential surface of the blade and an inner circumferential surface thereof. Therefore, an advantageous effect that a component having a large height may be mounted within a limited design height.

The present invention provides a fan motor which includes a housing, a stator disposed inside the housing, a rotor disposed inside the stator, a blade coupled to the rotor and a printed circuit board disposed under the blade, wherein the housing includes an upper housing and a lower housing, wherein a board coupling portion to which the printed circuit board is coupled is disposed concavely formed at a lower outer surface of the lower housing, and the first mounting portion of the printed circuit board is coupled to the board coupling portion, wherein the board coupling portion includes a component hole and the component hole is disposed between an outer circumferential surface of the blade and an inner circumferential surface thereof. Therefore, an advantageous effect that a component having a large height may be mounted within a limited design height.